Prediction of work piece geometry in electrochemical cavity sinking

A computer-implemented model for predicting ECM work piece geometry has been developed and experimentally verified with a commercial ECM machine for cavity sinking in copper and 302-stainless steel with 2N K NO₃ electrolyte. Constant tool piece feed rates of 7–10 × 10^?4 cm/s, and applied voltages of 11–25 V were used. The model predicts the dependence of work piece geometry on operating conditions and on the electrochemical and physical properties of the metal—electrolyte pair. Comparison of eight equilibrium and six unsteady state experimental cavity profiles in copper showed satisfactory agreement with predictions, as did five equilibrium profiles for cavity sinking in 302-stainless steel.     

Das Fachinformationssystem Hydrogeologie im Umweltinformationssystem Sachsen – Stand und praktische Anwendung

The branch information system “Hydrogeology” is part of the environmental information system of the federal state Saxony/Germany. The system comprises the decentral and the central data collection, central data storage and management as well as methods for data processing. As yet, data stocks and software were implemented particularly for point related data including applications for data collection, for the interpretation of pumping tests and grain size analysis as well as visualization. Maps are based on the implemented software applications and database structures. These data are an essential help in decisive processes for administrative objectives with a hydrogeologial and environmental background. Databases and methods for area-related data have been built up and already used for generation of maps.     

Associative symmetry versus independent associations in the memory for object-location associations.

The formation of associations between objects and locations is a vital aspect of episodic memory. More specifically, remembering the location where one experienced an object and, vice versa, the object one encountered at a specific location are both important elements for the memory of an event. Whether episodic associations are holistic representations of individual components or whether there are unidirectional, separately modifiable connections between them has been investigated nearly exclusively using verbal stimuli. A preliminary conclusion concerning this controversy is that verbal associations are, at least, highly correlated (M. J. Kahana, 2002). This theoretical debate, which in the past has undergone a major empirical effort, is still of relevance for the concurrent global matching models of associative memory (S. E. Clark & S. D. Gronlund, 1996). The authors used variations of a novel object-location learning paradigm to complement the accumulated evidence regarding the nature of episodic associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

电力变压器的套管、有载调压开关以及绝缘系统的在线监测和诊断

公用电力系统需要降低与其设备安装相关的运行和维护成本.降低成本的主要方法就是使用设备在线监测,并且要将基于时间的对变压器维护转变成基于工况的维护.由于监测系统的不断发展,维护和运行人员可以将其工作集中在其他更具有附加值的任务上.除此之外,由于电力市场管制的不断放开,公用电力系统将继续面临更加严峻的挑战.增加设备的负荷,降低维护费用以及延缓投资都是降低使用寿命成本的目的.这些措施同样也可能会造成较高的故障率,同时还会增加发生主要故障的风险.所以,本文的意图就是要在保证一定质量的电能供应同时尽量降低设备维护的成本费用(寿命管理).     

Organometallic Bonding in an Ullmann‐Type On‐Surface Chemical Reaction Studied by High‐Resolution Atomic Force Microscopy

The on‐surface Ullmann‐type chemical reaction synthesizes polymers by linking carbons of adjacent molecules on solid surfaces. Although an organometallic compound is recently identified as the reaction intermediate, little is known about the detailed structure of the bonded organometallic species and its influence on the molecule and the reaction. Herein atomic force microscopy at low temperature is used to study the reaction with 3,9‐diiododinaphtho[2,3‐b:2′,3′‐d]thiophene (I‐DNT‐VW), which is polymerized on Ag(111) in vacuum. Thermally sublimated I‐DNT‐VW picks up a Ag surface atom, forming a C? Ag bond at one end after removing an iodine. The C? Ag bond is usually short‐lived, and a C? Ag? C organometallic bond immediately forms with an adjacent molecule. The existence of the bonded Ag atoms strongly affects the bending angle and adsorption height of the molecular unit. Density functional theory calculations reveal the bending mechanism, which reveals that charge from the terminus of the molecule is transferred via the Ag atom into the organometallic bond and strengths the local adsorption to the substrate. Such deformations vanish when the Ag atoms are removed by annealing and C? C bonds are established.     

A Parallel Dynamic Binary Translator for Efficient Multi-Core Simulation

In recent years multi-core processors have seen broad adoption in application domains ranging from embedded systems through general-purpose computing to large-scale data centres. Simulation technology for multi-core systems, however, lags behind and does not provide the simulation speed required to effectively support design space exploration and parallel software development. While state-of-the-art instruction set simulators (Iss) for single-core machines reach or exceed the performance levels of speed-optimised silicon implementations of embedded processors, the same does not hold for multi-core simulators where large performance penalties are to be paid. In this paper we develop a fast and scalable simulation methodology for multi-core platforms based on parallel and just-in-time (Jit) dynamic binary translation (Dbt). Our approach can model large-scale multi-core configurations, does not rely on prior profiling, instrumentation, or compilation, and works for all binaries targeting a state-of-the-art embedded multi-core platform implementing the ARCompact instruction set architecture (Isa). We have evaluated our parallel simulation methodology against the industry standard Splash-2 and Eembc MultiBench benchmarks and demonstrate simulation speeds up to 25,307 Mips on a 32-core x86 host machine for as many as 2,048 target processors whilst exhibiting minimal and near constant overhead, including memory considerations.     

Close-range hyperspectral imaging for geological field studies: workflow and methods

Close-range hyperspectral imaging is a new method for geological research, in which imaging spectrometry is applied from the ground, allowing the mineralogy and lithology in near-vertical cliff sections to be studied in detail. Contemporary outcrop studies often make use of photorealistic three-dimensional (3D) models, derived from terrestrial laser scanning (lidar), that facilitate geological interpretation of geometric features. Hyperspectral imaging provides complementary geochemical information that can be combined with lidar models, enhancing quantitative and qualitative analyses. This article describes a complete workflow for applying close-range hyperspectral imaging, from planning the optimal scan conditions and data acquisition, through pre-processing the hyperspectral imagery and spectral mapping, integration with lidar photorealistic 3D models, and analysis of the geological results. Pre-processing of the hyperspectral images involves the reduction of scanner artefacts and image discontinuities, as well as relative reflectance calibration using empirical line correction, based on two calibrated reflection targets. Signal-to-noise ratios better than 70:1 are achieved for materials with 50% reflectance. The lidar-based models are textured with products such as hyperspectral classification maps. Examples from carbonate and siliciclastic geological environments are presented, with results showing that spectrally similar material, such as different dolomite types or sandstone and siltstone, can be distinguished and spectrally mapped. This workflow offers a novel and flexible technique for applications, in which a close-range instrument setup is required and the spatial distribution of minerals or chemical variations is valuable.     

Optimizing Disparity for Motion in Depth

Beyond the careful design of stereo acquisition equipment and rendering algorithms, disparity post‐processing has recently received much attention, where one of the key tasks is to compress the originally large disparity range to avoid viewing discomfort. The perception of dynamic stereo content however, relies on reproducing the full disparity‐time volume that a scene point undergoes in motion. This volume can be strongly distorted in manipulation, which is only concerned with changing disparity at one instant in time, even if the temporal coherence of that change is maintained. We propose an optimization to preserve stereo motion of content that was subject to an arbitrary disparity manipulation, based on a perceptual model of temporal disparity changes. Furthermore, we introduce a novel 3D warping technique to create stereo image pairs that conform to this optimized disparity map. The paper concludes with perceptual studies of motion reproduction quality and task performance in a simple game, showing how our optimization can achieve both viewing comfort and faithful stereo motion.     

Principles of Branching Morphology and Anatomy in Arborescent Monocotyledons and Columnar Cacti as Concept Generators for Branched Fiber‐Reinforced Composites

The branching of arborescent (tree‐like) monocotyledonous plants of the genus Dracaena or of columnar cacti differ considerably from that observed in other dicotyledonous or gymnosperm trees. The investigated ramifications exhibit distinctive morphological and anatomical features. In arborescent monocotyledons the side branches are attached to the main stem by a fiber‐reinforced tissue newly formed during secondary growth, clasping the main stem and finally resulting in a “flange‐mounted” structure. In the case of columnar cacti the most obvious feature is the pronounced constriction at the attachment point of the branches that is also mirrored in the lignified vascular tissue. One might argue that these characteristic morphological and anatomical features in regions exposed to high mechanical stresses represent structural weaknesses. However, the outer shape and the inner structures of the ramifications cause considerable stability and structural integrity of the stem‐branch connection under static and dynamic loading. Our results allow concluding that load‐adaptation in ramified plant structures is a result of a combination of optimization in outer shape and fiber arrangement within the ramifications. Numerical methods simulating the mechanical behavior based on data obtained from the studied plants support this assumption. A deeper understanding of the outer shape of the connection between shoot and branch as well as of the arrangement of the lignified vascular tissues in the branching region, may contribute toward alternative concepts for branched technical light‐weight‐structures. In particular for braided fiber‐reinforced composites this biomimetic approach might help to keep the demand on the available design space as small as possible.